Tone Correction Tables for Image Density Control
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Solution Overview
Problem
Image density adjustment in electrophotographic image forming apparatuses is challenging due to variations in developing agent state and environmental conditions, requiring frequent calibration and consumption of resources for measuring images across multiple sheets and halftoning types.
Innovation Solution
An image forming apparatus that includes sensors to measure image density, a control system to adjust image forming conditions, and a method for generating tone correction tables based on measurement data, allowing for automatic tone correction and reduced resource consumption by optimizing the number of test charts printed across different halftoning types.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If measuring images are formed on multiple sheets for all halftoning types to ensure accurate tone correction, then measurement precision and image density control accuracy are improved, but device complexity and operational time increase
Solution Approach 1:
The patent applies local quality by differentiating the measurement process based on halftoning types. Instead of uniformly measuring all halftoning types across multiple sheets, the system identifies and prioritizes measurement for specific halftoning types (e.g., image screen, text screen) based on their importance and usage frequency. This selective measurement approach maintains measurement precision for critical types while reducing overall calibration time.
Solution Approach 2:
The patent implements partial action by performing measurements only for necessary halftoning types rather than all possible types. The system determines the minimum required number of sheets and halftoning types to achieve adequate tone correction, avoiding excessive measurement that would waste time and resources. This partial measurement strategy balances accuracy requirements with operational efficiency.
2Manufacturing precision
If multiple measuring images are formed across different halftoning types to ensure comprehensive tone correction, then manufacturing precision is improved, but loss of substance (consumables) increases
Solution Approach 1:
The patent applies local quality by focusing measurement resources on specific halftoning types that have the most impact on image density control. Instead of creating measuring images for all halftoning types equally, the system identifies critical types and allocates measurement resources accordingly, reducing consumable usage while maintaining precision for the most important measurement objectives.
Solution Approach 2:
The patent implements partial action by performing measurements only for the minimum necessary number of halftoning types and sheets required for adequate tone correction. This selective approach avoids excessive consumable usage while still achieving the manufacturing precision needed for accurate image density control across different printing scenarios.
3Reliability
If comprehensive measurement across all halftoning types is performed to ensure accurate tone correction, then reliability is improved, but productivity decreases
Solution Approach 1:
The patent applies local quality by prioritizing measurement for halftoning types that are most critical for tone correction reliability. The system differentiates between high-priority types (such as image screen halftoning) and lower-priority types, allocating measurement resources to ensure accurate correction for the most impactful types while maintaining overall productivity.
Solution Approach 2:
The patent implements partial action by performing measurements only for the essential halftoning types needed for reliable tone correction, rather than comprehensively measuring all types. This selective measurement strategy maintains sufficient reliability for practical applications while significantly improving productivity by reducing the total measurement time and operational complexity.
Data Source
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AI summary
An image forming apparatus includes a conversion unit configured to convert image data based on a conversion condition corresponding to a type of halftoning, an image processing unit configured to perform the halftoning, an image forming unit configured to form an image, a measurement unit configured to measure a measuring image, an acquisition unit configured to acquire information related to the number of the sheets on which the measuring images are to be formed, and a controller configured to generate a first conversion condition corresponding to first halftoning based on a result of a first measuring image on a first sheet, and generate a second conversion condition corresponding to second halftoning based on a result of a second measuring image on a second sheet, wherein, based on the information, the controller controls whether to control the number of the first sheets is larger than the number of the second sheets.